Why Are There 5,280 Feet in a Mile?

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Why are there 5,280 feet in a mile, and why are nautical miles different from the statute miles we use on land? Why do we buy milk and gasoline by the gallon? Where does the abbreviation "lb" come from? Let's take a look at the origins of a few units of measure we use every day.

The Mile

The basic concept of the mile originated in Roman times. The Romans used a unit of distance called the mille passum, which literally translated into "a thousand paces." Since each pace was considered to be five Roman feet—which were a bit shorter than our modern feet—the mile ended up being 5,000 Roman feet, or roughly 4,850 of our modern feet.

If the mile originated with 5,000 Roman feet, how did we end up with a mile that is 5,280 feet? Blame the furlong. The furlong wasn't always just an arcane unit of measure that horseracing fans gabbed about; it once had significance as the length of the furrow a team of oxen could plow in a day. In 1592, Parliament set about determining the length of the mile and decided that each one should be made up of eight furlongs. Since a furlong was 660 feet, we ended up with a 5,280-foot mile.

The Nautical Mile

So if the statute mile is the result of Roman influences and plowing oxen, where did the nautical mile get its start? Strap on your high school geometry helmet for this one. Each nautical mile originally referred to one minute of arc along a meridian around the Earth. Think of a meridian around the Earth as being made up of 360 degrees, and each of those degrees consists of 60 minutes of arc. Each of these minutes of arc is then 1/21,600th of the distance around the earth. Thus, a nautical mile is 6,076 feet.

The Acre

Like the mile, the acre owes its existence to the concept of the furlong. Remember that a furlong was considered to be the length of a furrow a team of oxen could plow in one day without resting. An acre—which gets its name from an Old English word meaning "open field"—was originally the amount of land that a single farmer with a single ox could plow in one day. Over time, the old Saxon inhabitants of England established that this area was equivalent to a long, thin strip of land one furlong in length and one chain—an old unit of length equivalent to 66 feet—wide. That's how we ended up with an acre that's equivalent to 43,560 square feet.

The Foot

As the name implies, scholars think that the foot was actually based on the length of the human foot. The Romans had a unit of measure called a pes that was made up of twelve smaller units called unciae. The Roman pes was a smidge shorter than our foot—it came in at around 11.6 inches—and similar Old English units based on the length of people's feet were also a bit shorter than our 12-inch foot. The 12-inch foot didn't become a common unit of measurement until the reign of Henry I of England during the early 12th century, which has led some scholars to believe it was standardized to correspond to the 12-inch foot of the king.

The Gallon

The gallon we use for our liquids comes from the Roman word galeta, which meant "a pailful." There have been a number of very different gallon units over the years, but the gallon we use in the United States is probably based on what was once known as the "wine gallon" or Queen Anne's gallon, which was named for the reigning monarch when it was standardized in 1707. The wine gallon corresponded to a vessel that was designed to hold exactly eight troy pounds of wine.

The Pound

Like several other units, the pound has Roman roots. It's descended from a roman unit called the libra. That explains the "lb" abbreviation for the pound, and the word "pound" itself comes from the Latin pondo, for "weight." The avoirdupois pounds we use today have been around since the early 14th century, when English merchants invented the measurement in order to sell goods by weight rather than volume. They based their new unit of measure as being equivalent to 7000 grains, an existing unit, and then divided each 7000-grain avoirdupois pound into 16 ounces.

Horsepower

Early 18th-century steam engine entrepreneurs needed a way to express how powerful their machines were, and the industrious James Watt hit on a funny idea for comparing engines to horses. Watt studied horses and found that the average harnessed equine worker could lift 550 pounds at a clip of roughly one foot per second, which equated to 33,000 foot-pounds of work per minute.

Not all scholars believe that Watt arrived at his measurement so scientifically, though. One common story claims that Watt actually did his early tests with ponies, not horses. He found that ponies could do 22,000 foot-pounds of work per minute and figured that horses were half again stronger than ponies, so he got the ballpark figure of 33,000 foot-pounds of work per minute.

Where Did the Phrase 'Red Herring' Come From?

iStock.com/Mathias Darmell
iStock.com/Mathias Darmell

You may have seen a red herring in a recent book or movie, but you probably only realized it after the fact. These misleading clues are designed to trick you into drawing an incorrect conclusion, and they're a popular ploy among storytellers of all stripes.

If you've seen or read the Harry Potter series—and really, who hasn’t?—then you may recall some of the many instances where J.K. Rowling employed this literary device. That endearing plot twist about the nature of Snape's character, for example, is likely one of the longest-running red herrings ever written.

Sometimes they aren't even subtle. Agatha Christie's murder mystery And Then There Were None directly mentions red herring in reference to a character's death, and a statue of a red herring appears in Lemony Snicket's A Series of Unfortunate Events. Perhaps most blatantly, a character in the cartoon A Pup Named Scooby-Doo who was constantly being blamed for myriad crimes was named—you guessed it—Red Herring.

But where does this literary device come from, and why is it named after a fish? For a bit of background: herring are naturally a silvery hue, but they turn reddish-brown when they're smoked. Long before refrigerators were invented, this was done to preserve the fish for months at a time. They can also be pretty smelly. As Gizmodo's io9 blog points out, it was believed that red herring were dragged against the ground to help train hounds to sniff out prey in the 17th century. Another theory was that escaped prisoners used the fish to cover their tracks and confuse the dogs that tailed them.

However, io9 notes that red herring were actually used to train horses rather than dogs, and only if the preferred choice—a dead cat—wasn't available. The idea was that the horses would get used to following the scent trail, which in turn would make them less likely to get spooked while "following the hounds amid the noise and bustle of a fox hunt," notes British etymologist and writer Michael Quinion, who researched the origin of the phrase red herring.

The actual origin of the figurative sense of the phrase can be traced back to the early 1800s. Around this time, English journalist William Cobbett wrote a presumably fictional story about how he had used red herring as a boy to throw hounds off the scent of a hare. He elaborated on this anecdote and used it to criticize some of his fellow journalists. "He used the story as a metaphor to decry the press, which had allowed itself to be misled by false information about a supposed defeat of Napoleon," Quinion writes in a blog. "This caused them to take their attention off important domestic matters."

According to Quinion, an extended version of this story was printed in 1833, and the idiom spread from there. Although many people are more familiar with red herrings in pop culture, they also crop up in political spheres and debates of all kinds. Robert J. Gula, the author of Nonsense: Red Herrings, Straw Men and Sacred Cows: How We Abuse Logic in Our Everyday Language, defines a red herring as "a detail or remark inserted into a discussion, either intentionally or unintentionally, that sidetracks the discussion."

The goal is to distract the listener or opponent from the original topic, and it's considered a type of flawed reasoning—or, more fancifully, a logical fallacy. This application of red herring seems to be more in line with its original usage, but as Quinion notes: "This does nothing to change the sense of red herring, of course: it's been for too long a fixed part of our vocabulary for it to change. But at least we now know its origin. Another obscure etymology has been nailed down."

What Is the Shelf Life of Donated Eyes?

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iStock.com/Pedro_Turrini

Zoe-Anne Barcellos:

I can only answer for cornea and eye donation.

The FDA does all oversight (no pun intended) of organ disposition.

The main organs—heart, liver, pancreas, lungs, etc.—are transplanted within hours. They are just not viable if they are not being perfused constantly.

The other tissues—like bone, skin, tendons, etc.—do not need to be transplanted immediately. But I am not sure on the regulations of when they need to be transplanted.

With the eyes, there are four tissues that can be recovered.

We recover whole eyes for research and education purposes. These usually go much faster, but we can hold them up to a year.

Conjunctiva can also be recovered; conjunctiva is a clear covering over most of the eye (it is what gets irritated when you have pink eye). I have been working as a recovery tech for five years, and our office has not had a request for "conj" in all that time. I believe it is mostly used for research, but I could be wrong.

Sclera is the white area of your eye. It is fairly thick and flexible. If you have ever touched a reptile egg, that is what it reminds me of. We recover sclera for transplant. They use it for several things, but mainly to patch punctures. Similar to if you pop the inner tube of your bike and repair it. Sclera can also be used to repair ear drums. We can hold on to this for up to a year.

The main thing we recover is corneas. In the U.S., we must transplant these within seven days of recovery. (Recovery is usually within hours of death, but we can push it up to 20 hours after if needed.) Sometimes we have more corneas than we need, and then they are shipped overseas and transplanted up to 14 days after recovery. There is no real different outcome with the later transplant time, but the FDA in the U.S. made the rules. (You can sign up to be an organ, tissue, and eye donor here.)

This post originally appeared on Quora. Click here to view.

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